When flexibility finds its limits

You're typing up a memo in the low light and quiet of home late on a weekday night, no sound but the clatter of plastic keys, maybe the occasional yap of a neighbor's dog.

Could you have done the work during office hours? Sure. You know the routine: Just let phone calls drop into voicemail, tune out the office chatter and the fire-alarm testing. Focus.

But you've fully bought into this vaunted work/life-balance notion born of the '90s. And so you take the report home, you answer work calls during your commute, you read e-mail on Saturday.

And during "normal" hours? There's still plenty of work to do. But if you feel like hopping onto the Web to do some vacation planning, the boss will call it square. Right?

Well, maybe not.

Squeezing productivity out of workers in lean times means cutting back on perks. In recent months it has also meant much more aggressive policing of even the simplest of life-spillover issues – such as personal use of company computers and phones, and other on-the-clock doings sometimes called "undertime."

Flexible hours, it seems, bend more easily in one direction than the other. In the shifting power dynamic between employers and employees, many experts now say employers have regained the edge – and are getting tough about time.

Will they be reasonable about it? A poll by Management Recruiters International says workers who put in extra hours at the start of the day receive less credit than those who stay late (and are seen).

Such silliness may crimp the productivity that firms meant to boost – and cause workers to push back when they're more secure.